Explanation:
For question no 19
Force (F) = 20N
distance (d) = 5m
Work = F * d
= 20 * 5
= 100 J
Now
For question no 20
D. No matter how much force is applied the object must have motion for work to be done.
The correct answer is B. hyoid bone adapted for roaring
This wouldn't be helpful for hunters since it would actually make the lion more noticeable to its prey. If it's silent then it can creep up on it and get it easily, and roaring would not help him at all.
A. since the last cycle(fall in birth rate) has not occured yet.
I believe its Messenger RNA
The parasympathetic nervous system (PNS) controls homeostasis and the body at rest and is responsible for the body's "rest and digest" function. The sympathetic nervous system (SNS) controls the body's responses to a perceived threat and is responsible for the "fight or flight" response. The PNS and SNS are part of the ANS, or autonomic nervous system which is responsible for the involuntary functions of the human body.